A week after Apple updated its App Review Guidelines to permit retro game console emulators, a Game Boy emulator for the iPhone called iGBA has appeared in the App Store worldwide. The emulator is already one of the top free apps on the App Store charts.
It was not entirely clear if Apple would allow emulators to work with all and any games, but iGBA is able to load any Game Boy ROMs that users download from the web and open via the Files app on the iPhone. Accordingly, it seems like there are no game restrictions for emulators, unless Apple mistakenly approved iGBA on the App Store.
iGBA works with Game Boy, Game Boy Color, and Game Boy Advance games. It is important to note that it can be illegal to possess certain ROMs from game developers, but homebrew Game Boy games are typically in the clear.
iGBA appears to be a copy of Riley Testut's open-source GBA4iOS emulator, but with ads that can track users. GBA4iOS is the predecessor to Testut's current Nintendo game emulator Delta, which can be installed on the iPhone outside of the App Store, and will soon be available through his alternative app marketplace AltStore on iPhones in the EU. It is not clear if Testut plans to make Delta available in the App Store following the rule change.
Update: As noted by Parker Ortolani, the iGBA emulator has been removed from the App Store. Apple told us it removed the app for violating the company's app review guidelines related to spam and copyright, after learning that it was a knockoff app that copied another developer's submission (likely referring to GBA4iOS).
